Antioxidant activity and total phenol content of blackberries cultivated in a highland tropical climate/ Atividade antioxidante e fenois totais de amoras-pretas cultivadas em clima tropical de altitude

• Published in: Acta scientiarum. Agronomy Vol. 39; no. 1; p. 43
• Main Authors: Guedes, Mayara Neves Santos, Pio, Rafael, Maro, Luana Aparecida Castilho, Lage, Fabiola Fonseca, Patto de Abreu, Celeste Maria, Saczk, Adelir Aparecida
• Format: Journal Article
• Language: Spanish
• Published: Universidade Estadual de Maringa 01-01-2017
• ISSN: 1679-9275
• DOI: 10.4025/actasciagron.v39i1.28413

Blackberries are an important option for the diversification of fruit crops. However, there is currently no literature regarding plant cultivation in high-altitude tropical climates. Knowledge of the phenolic composition of blackberries is essential because variations in the levels of these components may exist between cultivars and may depend on environmental conditions. High performance liquid chromatography (HPLC) was used to evaluate the total phenol content of different blackberry cultivars (Arapaho, Brazos, Cainguangue, Cherokee, Choctaw, Comanche, Ebano, Guarani, Tupy and Xavante). Free radical scavenging activity in these cultivars was assayed using a DPPH test. The HPLC-UV chromatogram of blackberry fruit extracts at 280 nm revealed the presence of phenolic compounds. The results showed significant differences in the levels of phenolic compounds in the blackberry cultivars tested. Antioxidant activity was evaluated using the ABTS free radical and ranged from 2.7 [+ or -] 0.1 to 19 [+ or -] 2 pmole of Trolox equivalents per gram of sample (b.u.). These results are in good correlation with the phenolic contents of the blackberries tested. The Xavante blackberry cultivar had the highest levels of polyphenols that could be individually identified. Catechin polyphenols were found to be the main component in the blackberry varieties tested. Keywords: total phenols, free radicals, HPLC, Rubus spp. Amoras-pretas sao uma opcao importante para a diversificacao da fruticultura, no entanto, as informacoes sao restritas sobre plantas cultivadas no clima tropical de altitude. Conhecimento da composicao dos fenois antioxidantes na composicao das amoras-pretas e essencial, pois pode haver variacoes nos niveis destes componentes entre as cultivares e em favor das condicoes ambientais. A cromatografia liquida de alta eficiencia (HPLC) foi utilizada para avaliar o teor de fenois totais em frutos de diferentes cultivares de amora-preta (Arapaho, Brazos, Cainguangue, Cherokee, Choctaw, Comanche, Ebano, Guarani, Tupy e Xavante) e os potenciais radicais livres pelo teste DPPH. O esboco de extratos das amoras-pretas por HPLC-UV a 280 nm revelou a presenca de compostos fenolicos, com tempos de retencao e absorcao nas caracteristicas de UV-Vis. Os resultados mostraram que existem diferencas nos niveis de compostos fenolicos das amoras-pretas testadas. A atividade antioxidante foi avaliada por varrimento de ABTS de radicais livres, que variou de 2,7 [+ or -] 0,1 e 19 [+ or -] 2 pmoles equivalentes de trolox por grama de amostra (b.u.), que esta em boa correlacao com o conteudo de compostos fenolicos. A cultivar Xavante se destacou aos mais altos niveis de polifenois identificados individualmente e polifenois foi o principal componente nas cultivares. Palavras-chave: fenois totais, radicais livres, HPLC, Rubus spp.